Eccentric mechanism for converting a rotary movement into a reciprocating rectilinear movement of variable amplitude

ABSTRACT

A mechanism vehicle converts rotary motion to reciprocal linear or arcuate motion of variable amplitude consisting of a tubular housing having a rotary member therein with longitudinal slots for accomodating a slide piece. A block carrying an offset pivot bearing is mounted in said housing in spaced relation to said rotary member and a crank arm is positioned between said pivot and a lug which is in offset hinged relation to a slide positioned in said slots so that rotation of said crank arm generates a cone. A carrier bearing and assembly translates the rotation of said crank arm into reciprocal linear movement of a pair of slide blocks positioned in slots in said housing. A threaded adjustment member determines the spacing between said rotary member and said block carrying the pivot bearing so as to vary the stroke of the slide blocks in relation to the position of the carrier bearing on the cone generated by rotation of said crank arm.

United States Paten Sanz et al.

[451 Dec. 19, 1972 [54] ECCENTRIC MECHANISM FOR CONVERTING A ROTARY MOVEMENT INTO A RECIPROCATING RECTILINEAR MOVEMENT OF VARIABLE AMPLITUDE [72] Inventors: Manuel Claude Sanz, Geneva; Rene Weber, Bern, both of Switzerland [73] Assignee: Micromedic Systems, Inc., Philadelphia, Pa.

[22] Filed: Aug. 19, 1970 [21] Appl. No.: 27,217

Related US. Application Data [63] Continuation-in-part of Ser. No. 849,025, Aug. ll,

1969, Pat. NO. 3,614,896.

[52] US. Cl. .l...74/25 [51] .Int. Cl ..F16h 21/16 [58] Field of Search ..74/25, 27

[56] References Cited UNITED STATES PATENTS 2,829,526 4/1958 Riordan et al ..74/25 2,834,218 5/1958 Lovell ..74/25' 2,757,543 871956 Allan...- ..74/25 Primary ExaminerMilton Kaufman Assistant Examiner-Wesley S. Ratliff, Jr. Attorney-G. W. F. Simmons and Gerry Elman [57] ABSTRACT A mechanism vehicle converts rotary motion to reciprocal linear or arcuate motion of variable amplitude consisting of a tubular housing having a rotary member therein with longitudinal slots for accomodating a slide piece. A block carrying an offset pivot bearing is mounted in said housing in spaced relation to said rotary member and a crank arm is positioned between said pivot and a lug which is in offset hinged relation to a slide positioned in said slots so that rotation of said crank arm generates a cone. A carrier bearing and assembly translates the rotation of said crank arm into reciprocal linear'movement of a pair of slide blocks positioned in slots in said housing. A

threaded adjustment member determines the spacing between said rotary member and said block carrying the pivot bearing so as to vary the stroke of the slide blocks in relation to the position of the carrier bearing on the cone generated by rotation of said crank arm.

20 Claims, 9 Drawing Figures PATENTED nu: 19 m2 SHEET 1 0F 4 S Fm mm PATENTED 19 I97? 3. 706. 233

SHEET 2 OF 4 FIG.

PATENTED man 19 m2 3 706. 2 3 3 sum u or 4 ECCENTRIC MECHANISM FOR CONVERTING A ROTARY MOVEMENT INTO A RECIPROCATING RECTILINEAR MOVEMENT OF VARIABLE AMPLITUDE This is a continuation-in-part of an application Ser.

No. 849,025, filed in the United States Patent Office on tion of the crank-pin relative to the runner or spherical.

bearing, and an output member connected to the runner or hearing and constrained to move along a straight line which may be perpendicular to the axis of the cone.

Numerous mechanisms of this kind are known and they permit a symmetrical variation to be obtained of the amplitude of the reciprocating movement of the output member, i.e., the travel of the output member always takes place on opposite sides of an invariable mean position. The, high and low dead points are always, for a given setting of the amplitude, symmetrical with respect to this mean position. Now, in certain cases, it is useful for the high dead points (or the low .dead'points) always to coincide, whatever may be the amplitude, with an invariable position; the travel of the output member must then take place on opposite sides of a mean position which varies as a function of the amplitude. I

An object of this invention is to provide fine linear adjustments to a mechanism converting rotary motion into linear motion of variable amplitude when the mechanism is in operation.

A further object of this invention is to provide a novel mechanism for converting rotary motion into a reciprocal linear motion of fine accuracy.

A further object of the present invention is to provide an eccentric mechanism in which the amplitude of movement of the output member may be varied in an asymmetrical manner. For this purpose, according to the invention there is provided a mechanism of the kind defined wherein the crank-pin is a cylindrical rod, one end of which is secured to a cross-piece mounted on a transverse pivot whose ends slide in two longitudinal slideways provided within the rotary member and contained in a meridian plane of the latter. The other end of said rod carries a ball cooperating with a socket offset relative to the axis of rotation of the rotary member and carried by a slide member capable of sliding axially in a slideway which is parallel to this axis of rotation and which has means to prevent it from rotating around the latter. The said cross-piece and socket being ar! ranged so that the cone which is described by the axis of the crank-pin under the effect of the rotation of the rotary member has a generatrix which is parallel to the comprising a first movable slideway which permits said member to slide in a direction perpendicular to the plane containing said axis of rotation and said parallel generatrix. A spherical bearing may be used with grooves cut in its outer race. Said member is carried by a pair of blocks slidable in a second fixed slideway and which permits the member to slide along the said straight line at right angles to the axis of said cone, said output member being hinged to said pair of blocks. The said adjustment means comprises a first screw threaded member coaxial with said axis of rotation and cooperating with a second screw threaded member mounted on a fixed bearing.

One form of embodiment of the invention given by way of example only, is described below with reference to the accompanying drawings in which:

FIG. 1 is a longitudinal section;

FIG. 2 is a diagram showing two positions of one elementofFlG. l; I

FIG. 3 is a section on a larger scale of another element; 5

FIGS. 4, 5 and 6 are cross sections along the lines IV-IV, V-V, Vl-Vl respectively of FIG. 1;

. FIG. 7 is a sectional view of a preferred embodiment of the mechanism; I

FIG. 8 is a perspective view of and FIG. 9 is an exploded view of the crank-pin, lug and slide block shown in cross-section in FIG. 7.

The mechanism shown in FIG. 1 is housed in a cylindrical casing l which is itself carried by a framework 2. This mechanism comprises an input shaft 3 which by means notshown is rotatably driven as indicated by the arrow 4. The input shaft is rigid with a rotary member 5 rotating on bearings 6, 7. The rotary member 5 is hollow and is provided with slots 8, 9 in which are positioned for sliding movement, slide blocks 10, 11 carried by the ends of a transverse pivot 12. The slots 8, 9 are arranged in a meridian plane of the rotary member 5, so that the transverse pivot 12 is directed along a diameter of this rotary member. The transverse pivot is thus driven by the rotation of the member 5 around the axis 13 of the latter, and it can slide axially within the latter. A crank-pin l4, constituted by a cylindrical rod, carries at one of its ends a cross-piece 15 in the form of a rectangular parallel piped, which is secured thereto by a pin 16 and which is traversed by the transverse pivot 12 around which it can pivot. The other end of the crank-pin 14 carries an eccentric lug 17 on which is secured a ball 18 of a ball and socket joint. This ball is held in a socket 19 provided in a slide member 20 and it is retained in this socket by a plate 21 secured to the slide member by screws 22. The socket 19 thus houses the ball of the crank-pin l4 and this socket is offset relative to the axis 13. The distance between the axis 25 of the crank-pin l4 and the transverse pivot 12, on the one hand, and the eccentricity setting of the socket 19 in the slide member 20 on the other hand, are so chosen that taking into account the eccentric-settin g of the lug 17, there exists an angular position of the rotary member 5 called the high position in which the axis of the crank-pin is parallel to the axis of rotation 13. Moreover, the angular connection of the crank-pin 14 to its cross-piece 15 is such that when it is in this high the device of FIG. 7;

position, the lug 17 and the axis 25 are located in the same meridian plane as the rotary member 5, a meridian plane which, in FIG. 1, coincides with the plane of the drawing.

It will be seen that in the course of rotation of the member 5, the crank-pin 14 passes through a low position 14' shown in broken lines (see FIG. 2) and that, upon a complete revolution, its axis 25 describes a so-called eccentricity-setting cone, the apparent contour of which is delimited by the high position 25 and the low position 25' of this axis and which has a generatrix 25 parallel to the axis of rotation 13. This eccentricity-setting-cone has an apical opening A and its axis 26 is inclined relative to the axis of rotation 13 and meets the latter at the location where the transverse pivot 12 intersects it.

The slide member 20 is arranged in such a way as to be axially displaceable in the housing 1 which acts as a slideway therefor and a radial stud 23 which extends through a longitudinal slot 24 provided in the housing and prevents it from turning around the axis 13. The center of the socket is thus displaced along a straight line parallel to the axis of rotation l3.' I

On the crank-pin 14 is mounted a runner constituted by a member 27 provided with a hole delimited by two opposed conical surfaces 28, 29 (FIG. 3) each of which has an apical opening equal to the apical opening A of the eccentricity setting 25, 25. This arrangement permits the crank-pin to rotate and to slide in this runner while causing it to move without play over its conical movement. The member 27 is held between two rods 30, 31 which constitute a first slideway enabling it to slide in a direction 32 perpendicular to the meridian plane defined by the axis of rotation 13 and by the high generatrix 25 of the eccentricity-setting cone. These two rods extend through the housing 1 via two slots 33, 34 and are assembled by means of two crosspieces 35, 36 (FIG. These cross-pieces constitute blocks which in their turn slide in two grooves 37, 38 constituting a second slideway which enables the member 27 to move in a direction 39 perpendicular to the axis 26 of the cone of eccentricity. The rod 31 extends beyond the blocks 35, 36 and its ends 40, 41 serve as pivots on which is pivoted a yoke 42. In the example described, this yoke is in turn pivoted on a lever 43 guided in a sliding bearing 44 arranged in the framework 2. The lever 43 can be attached to a crank arm (not shown) for extending the movement out beyond the bottom of framework 2.

The slide member 20 is rigid with a rod 45 which constitutes the end of a screw 46 and which cooperates with nut 47 carried by a sleeve 48. This latter rotates in a bearing constituted by three resilient rods 51, 52, 53 (FIG. 6) located in a plane perpendicular to the axis of rotation 13 and arranged in such a way as to form a triangular frame which circumscribes this sleeve: the ends 54-59 of these rods are held in a bearing support 60 while their middle points 61, 62, 63 cooperate with a circular groove 64 in the sleeve 48. This triangular frame thus constitutes a resilient bearing, which may be advantageous when there is a risk of alignment defects and when it is desirable to eliminate the stresses which may result therefrom.

The sleeve 48 carried a knob 65 secured to it by a pin 66. The rod 45, screw 46, nut 47, sleeve 48 and know 65 constitute control means enabling the axial position of slide member 20, and consequently of crank-pin 14 and cross-piece 15 to be varied.

The operation of this mechanism will be readily understood. As has already been described, the crank-pin 14, due to the fact that it is angularly rigid with the rotary member 5 via the slots 8, 9, transverse pivot 12 and cross-piece 15, rotates around the socket 19, so that its axis 25 describes the eccentricity-setting cone shown diagrammatically by the lines 25, 25' which represent two particular generatrices, the high generatrix 25 and the low generatrix 25'. Consequently the center of the runner 27, which is guided in the slideways 30,

31 and 37, 38 cannot leave a plane perpendicular to the axis 26 of this cone, and is obliged to describe the circle constituted by the intersection of the cone with the plane. The output member has thus imparted thereto in axial position of slide member-20, and thus of crank pin l4 and cross-piece 15 is varied, the distance between the apex of the cone of eccentricity 25, 25' and the plane in which the runner moves is also varied, this plane being defined by the directions 32 and 39. In this way the diameter of the circle constituted by the intersection of this cone and plane is varied and hence the amplitude of the alternating movement communicated to the output member is also varied. As the dimensions of the various parts have been chosen in such a way that the high generatrix 25 of the eccentricity-setting cone may lie parallel to the axis of rotation 13, the high dead point of this reciprocating movement is independent of the axial position of the crank-pin. There is thus obtained an asymmetric variation of the amplitude and the mean position, on either side of which the movement of the output member takes place and varies in the same manner.

The modification in amplitude of the stoke maybe made both while the rotary member is rotating as well as when it is stationary. It may be advantageous, in the latter case, to permanently immobilize the crank-pin in its high position, where its axis 25 coincides with the high" generatrix .of the cone of eccentricity. The modification of the axial position of the slide member 20 necessary for changing the amplitude then has no effeet on the output member which remains perfectly stationary. In order to arrive with certainty atthis result, the mechanism is provided with a resilient detent which may be constituted by a ball trapped in a socket 71 arranged in the casing 1. This ball is urged by an elastomeric spring 72 so as to cooperate with a longitudinal slot 73 on the external lateral surface of the rotary member 5 in a suitable angular position. There are usually two slots 73 and two balls 70. This arrangement is advantageous when the mechanism is used to actuate a piston pump which transports a fluid. One can thus be certain, by modifying the amplitude adjustment when the mechanism is stationary, that this modification of adjustment will not cause unwanted displacements of fluid. It is an advantage which renders this mechanism particularly suitable for actuating pumps for dosing microanalysis apparatus, in particular biochemical micro'analysis.

The mounting of the ball 18 on the lug 17 offset relative to the axis 25 of the crank-pin is not indispensable. This arrangement is provided in order to permit the runner to slide up to the moment when the plane in which it moves passes through the center 50 of the eccentricity-setting cone, i.e. to permit the amplitude adjustment range to be extended up to the value zero. If this requirement is not necessary, the ball can then be fixed in a position coaxial with the axis 25, i.e. to use a central lug 17.

It is, of course, possible to provide a system enabling the axial position of the slidemember 20 to be measured and this system can be graduated directly according to the value of the amplitude.

Finally, it may be advantageous to limit the axial movement of the slide member 20 in order to prevent the runner from coming into contact with the ball 18 or with the cross-piece 15. This may be achieved, for example, by suitable dimensioning the length of the slot 24 and positioning it longitudinally in the desired.

manner.

FIGS. 7-9 show a preferred embodiment of the device which performs the same movements as the device of FIGS. l-6 but incorporates certain changes in the design of the device.

The device is generally designated by 400 in FIG. 7. It is housed in a cylindrical casing 401 having annular internal grooves 402 at one end to receive snap rings 430. The opposite end has an annular internal groove 403 which is adapted to receive a snap ring 407. A tubular member 404 is mounted for rotary movement within casing 401 on bearing surfaces 405 and is prevented from sliding longitudinally within 401 by rings 407 and 407'.

There are two parallel juxtapositioned longitudinal slots or slideways 406 in the inner surface of member 404. These are similar to slots 8 in the embodiment shown in FIGS. 1-6.

A solid cylindrical member 408 is mounted for longitudinal sliding movement within the casing. It is prevented from rotating relative to the casing by a screw 410 carrying a rider 411 threaded into a hole 409. Rider 411 cooperates with a slot 412.

A cylindrical bore 413 located in member 408 receives a hollow cylindrical insert 414, press fitted therein or screwed therein. The internal diameter of insert 414 is pinched as at 415. A flange 416 maintains the insert 414 against sliding movement within member 408. A jeweled ball 41 7 is received in the end portion of insert 414 and is maintained there by a spring 419 pushing against a member 418. A screw threaded stud 420 keeps the spring in compression within the insert member.

A coaxial bore 423 receives the end portion 422 of a threaded rod 421. Portion 422 is either press fitted into bore 423 or fastened therein for non-rotative movement. An internally threaded sleeve 424 engages a reduced diameter threaded portion 425 and a portion of the larger diameter sectionof 421. In the position shown in FIG. 7, the stroke would be adjusted to an in termediate length between zero and its maximum length. Sleeve 425 is mounted in a spherical portion 428 of a bearing having its outer race 429 between ring 430. The end of portion 425 has a slot 426 therein and a pin 427. Slot 427 and pin 427 are adapted to cooperate with a suitable key or turning knob (not shown) which may be inserted into slot 426 and retained therein by pin 427. By turning sleeve 424, rod 421 moves longitudinally in either direction, depending on the direction of rotation.

Ball 417 receives an extension member 492 of a crank-pin 431. The extension member 492 is offset from the axis of pin 431 in the same manner as lug 17 is offset from crank-pin 14 in the embodiment of the device shown in FIGS. 1-6. Referring now to FIG. 9, crank-pin 431 is connected to a swivel member 432 having swivel studs 433. Member 432 mounts in bearing member 434 in rectangular cut-out portion 435 and swivels therein on studs 433 which are received in holes 437. Member 434 has the general shape of a semi-circle but is slightly over for a reason to be explained. The outer circumference of member 432 has an arcuate raised portion 438 which is relieved as at 439 to accomodate the end of studs 433. 1 i

Member 432 is received with a slide member 440 which is generally rectangular with opposite parallel slide surfaces 443, 444. Member 440 has a generally semi-circular cut-out portion 441 which is slightly larger than a semi-circle or 180. An annular notch 442 extends around the arcuate edge of the cut-out portion and is adapted to receive raised portion 438 of member 440. The reason that member 434 and cut-out portion 441 of member 440 are slightly larger than a 180 semicircle is to allow member 434, usually made of steel or a like metal, to snap into member 440, usually made of bronze or like material.

The surfaces 443, 444 of member 440 are adapted to slide in longitudinal slots 406 of member 404.

Crank pin 431 is mounted for sliding movement within the central portion of a spherical bearing 445,

the outer race 446 of which is grooved as at 447 to slidably fit between rods 448, 449. Rods 448 and 449 are fixed to cross pieces 450 and 451, respectively. Rod 448 extends through the cross pieces in order to hingedly accomodate arms 454 and 455 of member 456, shaped like a turning fork. In FIG. 8, it is seen that member 456 has a lower depending portion 457 which has a rectangular aperture through which extends stroke bar 460. A set screw 458 in bore 457 of bar 460 maintains the relationship between bar 460 and member 456.

Bar 460 is mounted for rotative movement on pin 461 which is mounted in mounting block 462 in cut-out portion 463. Block 462 has a recessed area 464 which receives a machine screw 465. Screw 465 passes through a bore in the block and is threadably engaged in in threaded bore 467 in the base of casing 401. An insert 466 spaces block 462 from the casing401.

At the forward end of rod 460 is a small diameter bore 467 for receiving a force member (not shown) adapted to transmit the stroke to a piston or other device. A bore 468 receives a set screw (not shown) for retaining a force member in the end of bar 460.

Mounted on the extending portion of member 404 is a gear 470. Gear 470 has teeth 472 and a circular slot which receives the end 471 of member 404. Gear 470 also has reduced diameter portions 473 and 474 which receive a cap member 475. Gear 470 and cap member 475 have the same diameter bores, 479 and 478, respectively. A set screw 480 secures cap member 475 to reduced diameter portion 474.

The alternate embodiment functions in the same manner as the mechanism shown in FIGS. 1-6. Crank pin 431 describes a cone in its rotation and a parallel to the axis of rotation of member 404 when at the top of its rotation position. To adjust the are through which bar 460 moves by turning sleeve 424 which is fixed in its longitudinal movement. Turning sleeve 424 moves rod 421 longitudinally in either direction thus shortening or increasing the distance through which cross pieces 450 and 451 move. The arcuate movement of the end of bar 460 is sinusoidal due to the nature of the kinematic arrangement of the mechanism.

The device can be used to provide sinusoidal movement to any other device, such as a piston and cylinder. It is an improvement over straight reciprocal linear movement which tends to start off quickly and diminish quickly. In the movement provided by the instant device, the maximum speed of movement occurs in the middle of the travel distance with acceleration and' deceleration phases before and after this point of maximum speed.

And, more importantly, the length of travel, whether arcuate or linear can be linearly adjusted either before or during the movement of the device with a great degree of accuracy.

While only two embodiments of the mechanism have been shown, it is apparent that many changes will occur obvious to those skilled in the art within the scope of the appended claims.

What is claimed is:

1. A mechanism for converting rotary motion to reciprocal, rectilinear motion comprising an elongated housing, a hollow cylindrical member mounted for non-longitudinal, rotarymovement within a portion of said housing, pivot means offset from the axis of rotation of said cylindrical member and mounted for nonrotary longitudinal movement within a further portion of said housing, adjustment means operatively connected to said pivot means and adapted to move said pivot means longitudinally within said further portion of said housing, longitudinal slot means within said cylindrical member, crank means having one end pivotally attached to said pivot means, slide means mounted in said slot means for longitudinal movement, pivotal connection means on said slide means, the other end of said crank means extending within said hollow cylindrical member and attached to said pivotal connection means, said crank means adapted to generate a cone upon rotation of said cylindrical member and means slidably associated with said crank means and said housing and adapted to translate the movement of said crank means into reciprocal movement whereby the stroke of the reciprocal movement may be. varied by moving said pivot means longitudinally within said housing.

2. A mechanism as in claim 1 wherein said crank means comprises a-rod and said pivotal connection means comprises a lug, said lug being pivoted in said slide means and the end of said rod being pivoted in said lug.

3. A mechanism as in claim 2 wherein said motion translating means comprises a member slidably mounted on said rod and mounted between guide means for lateral movement, said guide means being attached to at least one slide member mounted for linear sliding movement in relation to said housing.

4. A mechanism as in claim 3 wherein said member slidable mounted on said rod is a spherical bearing, the outer raceof said bearing having juxtapositioned concave grooves therein for receiving said guide means.

5. A mechanism as in claim 3 wherein said guide means comprise two parallel rods.

6. A mechanism as in claim 3 including two slide members, slots in opposite sides of said housing, said slide members being positioned in said slots and being held therein by said guide means extending therebetween.

7. A mechanism as in claim 6 wherein said member slidably mounted on said rod is a spherical bearing and said guide means are a pair of parallel rods mounted to said slide'members, said spherical bearing mounted between said parallel rods for lateral movementtherein.

8. A mechanism as in claim 1 wherein saidpivot means comprises a cylindrical member having an off center bore, bearing means located in said ,bore, spring means resiliently holding said bearing in said bore, said rod being connected to said bearing for rotation.

9. A mechanism as in claim 8 wherein said rod is connected to said bearing at a point offset from its central axis whereby when said crank rod isat the top of its rotation thestroke may be adjusted to zero.

10. A mechanism as in claim 1 wherein said means adapted to move said pivot means longitudinally comprises a v longitudinally extending threaded shaft mounted to said pivot means, an internally threaded sleeve means mounted within said housing for rotational movement therein, said sleeve means engaging said shaft means and means on the end of said sleeve means to rotate said sleeve means whereby said pivot means can be moved longitudinally within said housing.

11. A mechanism for converting rotary motion into reciprocal sinusoidal motion, said mechanism comprising a housing, rotary means mounted for rotation within said housing,'longitudina1 guide means in said rotary means, pivot means'mounted for incremental longitudinal movement within said housing, motion translating means slidably mounted in said guide means and pivotally mounted to said pivot means to thereby generate a cone form upon rotation of said rotary means, first slide means mounted on said housing for sliding movement relative thereto and pivotally and slidably connected to said motion translating means to thereby slidably reciprocate as said motion translating means generates a cone in response to the rotation of said rotary means, and adjustment means attached to said pivot means and adapted to incrementally move said pivot means longitudinally within said housing to vary the amount of travel of said slide means.

12. A mechanism as in claim 11 wherein said motion translating means includes a crank rod, one end of said crank rod attached to said pivot means, the other end being attached to a second slide means, said guide means comprising a pair of juxtapositioned longitudinal slots in said rotary means, said second slide means engaging said longitudinal slots, and said crank rod attached to said secondslide means in an offset fashion whereby said crank arm describes a cone as the rotary means rotates thereby causing the crank arm to rotate.

13. A mechanism as in claim 12 wherein said motion translating means further comprises a bearing member slidably mounted on said crank rod, a pair of laterally extending guide members extending through said housing and connected to said first slide means, said bearing member slidably mounted between said guide members for lateral movement as said crank arm rotates and describes a cone.

14. A mechanism as in claim 13 wherein said bearing member is a spherical bearing, the outer race of said bearing having juxtapositioned concave grooves therein for receiving said guide members.

15. A mechanism as in claim 13 wherein said pair of guide members comprise two parallel rods.

16. A mechanism as in claim 13 wherein said housing is tubular and has slots opposite sides thereof, said slots being substantially perpendicular to the axis of the cone described by said crank rod, said first slide means being positioned in said slots.

17. A mechanism as in claim 16 including an arm member, one end of said arm member being pivotally attached to one end of said housing, and bracket means connecting said arm member with said first slide means.

18. A mechanism as in claim 11 wherein said adjustment means comprises a longitudinally extending threaded shaft attached to said pivot means, an internally threaded sleeve means mounted in said housing for rotational movement therein, said sleeve means engaging said shaft to move said shaft upon rotation of said sleeve means.

19. A mechanism as in claim 11 including a gear means attached to the end of said rotary means, said gear means adapted to be driven to rotate said rotary means.

20. A mechanism as in claim 11 wherein said motion translating means includes a second slide means, said slide means mounted in said longitudinal guide means. 

1. A mechanism for converting rotary motion to reciprocal, rectilinear motion comprising an elongated housing, a hollow cylindrical member mounted for non-longitudinal, rotary movement within a portion of said housing, pivot means offset from the axis of rotation of said cylindrical member and mounted for nonrotary longitudinal movement within a further portion of said housing, adjustment means operatively connected to said pivot means and adapted to move said pivot means longitudinally within said further portion of said housing, longitudinal slot means within said cylindrical member, crank means having one end pivotally attached to said pivot means, slide means mounted in said slot means for longitudinal movement, pivotal connection means on said slide means, the other end of said crank means extending within sAid hollow cylindrical member and attached to said pivotal connection means, said crank means adapted to generate a cone upon rotation of said cylindrical member and means slidably associated with said crank means and said housing and adapted to translate the movement of said crank means into reciprocal movement whereby the stroke of the reciprocal movement may be varied by moving said pivot means longitudinally within said housing.
 2. A mechanism as in claim 1 wherein said crank means comprises a rod and said pivotal connection means comprises a lug, said lug being pivoted in said slide means and the end of said rod being pivoted in said lug.
 3. A mechanism as in claim 2 wherein said motion translating means comprises a member slidably mounted on said rod and mounted between guide means for lateral movement, said guide means being attached to at least one slide member mounted for linear sliding movement in relation to said housing.
 4. A mechanism as in claim 3 wherein said member slidable mounted on said rod is a spherical bearing, the outer race of said bearing having juxtapositioned concave grooves therein for receiving said guide means.
 5. A mechanism as in claim 3 wherein said guide means comprise two parallel rods.
 6. A mechanism as in claim 3 including two slide members, slots in opposite sides of said housing, said slide members being positioned in said slots and being held therein by said guide means extending therebetween.
 7. A mechanism as in claim 6 wherein said member slidably mounted on said rod is a spherical bearing and said guide means are a pair of parallel rods mounted to said slide members, said spherical bearing mounted between said parallel rods for lateral movement therein.
 8. A mechanism as in claim 1 wherein said pivot means comprises a cylindrical member having an off-center bore, bearing means located in said bore, spring means resiliently holding said bearing in said bore, said rod being connected to said bearing for rotation.
 9. A mechanism as in claim 8 wherein said rod is connected to said bearing at a point offset from its central axis whereby when said crank rod is at the top of its rotation the stroke may be adjusted to zero.
 10. A mechanism as in claim 1 wherein said means adapted to move said pivot means longitudinally comprises a longitudinally extending threaded shaft mounted to said pivot means, an internally threaded sleeve means mounted within said housing for rotational movement therein, said sleeve means engaging said shaft means and means on the end of said sleeve means to rotate said sleeve means whereby said pivot means can be moved longitudinally within said housing.
 11. A mechanism for converting rotary motion into reciprocal sinusoidal motion, said mechanism comprising a housing, rotary means mounted for rotation within said housing, longitudinal guide means in said rotary means, pivot means mounted for incremental longitudinal movement within said housing, motion translating means slidably mounted in said guide means and pivotally mounted to said pivot means to thereby generate a cone form upon rotation of said rotary means, first slide means mounted on said housing for sliding movement relative thereto and pivotally and slidably connected to said motion translating means to thereby slidably reciprocate as said motion translating means generates a cone in response to the rotation of said rotary means, and adjustment means attached to said pivot means and adapted to incrementally move said pivot means longitudinally within said housing to vary the amount of travel of said slide means.
 12. A mechanism as in claim 11 wherein said motion translating means includes a crank rod, one end of said crank rod attached to said pivot means, the other end being attached to a second slide means, said guide means comprising a pair of juxtapositioned longitudinal slots in said rotary means, said second slide means engaging said longitudinal slots, and said crank rod attached to said second slide means in an ofFset fashion whereby said crank arm describes a cone as the rotary means rotates thereby causing the crank arm to rotate.
 13. A mechanism as in claim 12 wherein said motion translating means further comprises a bearing member slidably mounted on said crank rod, a pair of laterally extending guide members extending through said housing and connected to said first slide means, said bearing member slidably mounted between said guide members for lateral movement as said crank arm rotates and describes a cone.
 14. A mechanism as in claim 13 wherein said bearing member is a spherical bearing, the outer race of said bearing having juxtapositioned concave grooves therein for receiving said guide members.
 15. A mechanism as in claim 13 wherein said pair of guide members comprise two parallel rods.
 16. A mechanism as in claim 13 wherein said housing is tubular and has slots opposite sides thereof, said slots being substantially perpendicular to the axis of the cone described by said crank rod, said first slide means being positioned in said slots.
 17. A mechanism as in claim 16 including an arm member, one end of said arm member being pivotally attached to one end of said housing, and bracket means connecting said arm member with said first slide means.
 18. A mechanism as in claim 11 wherein said adjustment means comprises a longitudinally extending threaded shaft attached to said pivot means, an internally threaded sleeve means mounted in said housing for rotational movement therein, said sleeve means engaging said shaft to move said shaft upon rotation of said sleeve means.
 19. A mechanism as in claim 11 including a gear means attached to the end of said rotary means, said gear means adapted to be driven to rotate said rotary means.
 20. A mechanism as in claim 11 wherein said motion translating means includes a second slide means, said slide means mounted in said longitudinal guide means. 